[JENA-1877] Wrong results for non-optimized query

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Information Provided
• Affects Version/s: Jena 3.14.0
• Component/s: ARQ
• Assignee: Unassigned
• Reporter: Jeremy Coulon
• Created: 01/Apr/20 14:20
• Updated: 16/Apr/20 21:39
• Resolved: 16/Apr/20 21:39

Description

I noticed that the attached query gives correct results with:

./bin/arq --data=data.ttl --query=bnode01.rq --explain --optimize=on

while it gives wrong results with:

./bin/arq --data=data.ttl --query=bnode01.rq --explain --optimize=off

Without optimization, ARQ algebra has 2 different 'extend' op with 'bnode(?s)' expression.

With optimization, ARQ algebra merges these ops into a single op 'extend'.

 

I tried debugging and I think that 'E_BNode.evalSpecial()' takes the same 'binding' object for each call in optimized mode but different 'binding' objects for non-optimized mode. This function relies on reference-equality.

 

data.ttl

bnode01.rq